* Dumoulin attacks near foot of of last climb * Ailing former champion Contador pulls out * Froome controls rivals, leads Yates by 16 seconds By Julien Pretot ARCALIS, Andorra, July 10 (Reuters) - Tom Dumoulin of the Netherlands attacked near the foot of the final climb to win the ninth stage of the Tour de France in extreme weather conditions as Alberto Contador pulled out of the race on Sunday. Giant Alpecin rider Dumoulin, sixth in last year's Vuelta, was the strongest of the day's breakaway riders, taking a solo victory in a deafening hailstorm after riding most of the day in temperatures nearing 40 degrees Celsius. Briton Chris Froome retained the overall leader's yellow jersey after controlling his closest rivals in the ascent to Arcalis, a 10.1km effort at an average gradient of 7.2 percent. More...